For infant disposable diapers, many types of anti-leakage mechanisms have heretofore been proposed for the purposes of preventing leakage of liquid from the leg portions. In one example, hydrophobic three-dimensional gathers are formed on an inner side of each leg gather in the longitudinal direction of the diaper, and the three-dimensional gathers are collapsed inwardly. The three-dimensional gathers tend to be raised to some extent when the diaper is in use, and serve as antileakage portions owing to their hydrophobic properties, thereby enhancing the receiving characteristics of discharged material and preventing liquid leakage from the leg portions, which would otherwise occur in accordance with the motion of the diaper wearer.
Further, in the above-mentioned three-dimensional gathers, it is true that the receiving characteristics of the diaper for discharged material are enhanced due to so-called pocket portions which are formed by the three-dimensional gathers. However, there are many instances where the three-dimensional gathers collapse under e.g. body pressure of the diaper wearer when the diaper is in use, and therefore the advantageous effects attributable to the three-dimensional gathers can not be fully exhibited. Furthermore, depending on the motion of the diaper wearer, liquid diffuses in various directions within the diaper and frequently leaks outside the three-dimensional gathers. In such cases, the outside area of the three-dimensional gathers is hydrophobic and no absorbent member is provided. Accordingly, the liquid which has leaked is allowed to flow directly outside the disposable diaper without being absorbed. Moreover, since the leg gathers themselves are not three-dimensional, the leg gathers do not have such an anti-leakage function, as the above-mentioned three-dimensional gathers, and the leg gathers cannot prevent liquid from leaking.
As means for solving such problems, there can be contemplated, among others, that the expanding/contracting force of the elastically expansible members disposed on the free edge portions of the three-dimensional gathers is increased. However, any attempt for merely increasing the expanding/contracting force is encountered with disadvantages such as the diaper is contracted in size and badly irritates the skin of the diaper wearer.
Further, in the above-mentioned three-dimensional gathers, there are many instances where discharged material is locally absorbed. As a result, in spite of the feature that the absorbent member is arranged over the entire surface of the diaper, it is only a part of the absorbent member that actually contributes to absorption of the discharged material and therefore, the inherent absorbing performance of the absorbent member can not be fully realized in many cases. Furthermore, due to local absorption of the discharged material, particularly due to local absorption of the discharged material at the discharging area and its adjacent areas (i.e., the crotch portion of the diaper), it sometimes occurs that the diaper slips down or sags to degrade the fit. The result is that the discharged material tends to leak and the diaper wearer finds it difficult to move. Moreover, in some instances, the diaper is partly expanded (puffed out), which spoils its outer appearance.
It is, therefore, an object of the present invention to provide a disposable diaper, in which liquid can assuredly be absorbed and prevented from leaking when the liquid tends to disperse in various directions in accordance with motion of the diaper wearer.
Another object of the present invention is to provide a disposable diaper, in which the inherent absorbing performance of an absorbent member can fully be exhibited by preventing local absorption of the discharged material, and unfavorable occurrences such as slip-down, leaking, bagginess, and the like, do not happen even by the weight of the discharged material.